Best to purchase your tickets online and print the...

Best to purchase your tickets online and print them and arrive 30 mins before opening time (there will be a queue already). The queue to the entrance moves fairly quick, we waited around 25-30 minutes after arriving at opening time (10am on Monday). I've been advised to head straight to the Crown jewels as soon as you walk in and it worked, we walked in without a queue, spent around 45 minutes in and when we walked out there was already more than 80 people queueing. Overall visiting every tower and building inside took us just under 4 hours. Bear in mind there's lots of stairs and uneven surfaces when you visit.